Engineering Questions with Answers - Multiple Choice Questions

# Aerodynamics – The Symmetric Airfoil – 1

1 - Question

Is symmetric airfoil with good lift to drag ratio is used for an aircraft wing?
a) True
b) False
Explanation: The symmetric airfoil with good lift to drag ratio is used for an aircraft wing, this will be translated into lower fuel consumption, shorter take-off and landing times, and shorter runways. Airfoil With backward facing will get high lift coefficient.

2 - Question

Is fluid flows across the airfoil with a backward facing step?
a) False
b) True
Explanation: The fluid flows across the airfoil with a backward facing step, a vortex region which has a lower pressure will be created. This will reduce the wake region of the symmetric airfoil. The idea of the backward facing step airfoil originates from the idea of dimples on the golf ball where the dimples induce the creation of a small vortex region.

3 - Question

Is NACA 0012 is symmetric airfoil?
a) True
b) False
Explanation: The NACA 0012 is symmetric airfoil because the mean camber line and chord line intersect in the same line.so, there is no camber in the NACA 0012 airfoil. That the reason the first and second digits are will become zero, and the thickness of NACA 0012 airfoil is 12 percent.

4 - Question

What is the thickness of NACA 0002 airfoil?
a) 3%
b) 1%
c) 0%
d) 2%
Explanation: The thickness of the NACA 0002 airfoil is 2 percent. There is no camber in the NACA 0002 airfoil because of the mean camber line and chord line intersect in the same line, so the position maximum camber in the NACA 0002 airfoil is zero.

5 - Question

Is wake behind the airfoil exhibits a continuous vortex?
a) False
b) True
Explanation: The wake behind the airfoil exhibits a continuous vortex shedding pattern below 8 degrees incidence angle of NACA 0002 and below 7 degrees incidence angle for NACA 0012 at remolds number 1000 it exhibits the continuous vortex.

6 - Question

How many types the wake structure is classified?
a) 2
b) 3
c) 5
d) 4
Explanation: The wake structure is classified into five different modes according to their pattern obtained from instantaneous and mean vorticity fields by also taking into account the amplitude spectrum of the lift coefficient.

7 - Question

How lift is calculated?
a) Perpendicular to the direction of motion
b) Parallel to the direction of motion
c) opposite to the direction of motion
d) relative to the direction of motion
Explanation: An airfoil shaped body moved through a fluid produces an aerodynamic force. The component of this force perpendicular to the direction of motion is called lift. The lift will oppose the motion and it produces the lift.

8 - Question

Is upper and lower curvatures are equal in symmetric airfoil?
a) True
b) False
Explanation: The upper and lower curvature are equal in the symmetric airfoil because there is no maximum camber in the symmetric airfoil when compare to cambered airfoil it does not produce high lift, so these are used in the subsonic flights.

9 - Question

Is symmetric airfoil produce positive lift?
a) False
b) True